Don’t run a robot vacuum without cliff sensors near stairs.

No. It will fall.

Robot vacuums without cliff sensors are basically blind to drops. They rely on bumpers and optical sensors to navigate, but none of that tells them “there’s a two-meter drop ahead.” They’ll roll right off the edge like a Roomba chasing a pizza crumb off a cliff.

Even vacuums with cliff sensors sometimes fail if the sensors get dirty or the drop is dark-colored. Without them, it’s not a question of if it falls, but when. You can put up physical barriers like baby gates, but then you’re defeating the whole point of a robot vacuum — letting it run unattended.

Bottom line: don’t trust gravity to a machine that can’t see it. If your model lacks cliff sensors, keep it on a single floor or stay within earshot. Or just get a cheap threshold strip for the stairs. Future you doesn’t want to sweep up a broken bot.